The present invention relates to radio-frequency identification (RFID) systems, including RFID tags, readers, and activators. The invention also relates to electronic article surveillance (EAS) systems, including EAS tags, alarms, activators, and deactivators. The invention also relates to RFID and EAS apparatus and methodology that enables the RFID functionality of a tag to be deactivated at substantially the same time that the EAS functionality is deactivated and with the same device that deactivates the EAS functionality.
Automatic identification is the broad term applying to a host of technologies that are used to help machines identify objects. Automatic identification is often coupled with automatic data capture. Accordingly, companies that want to identify items are able to capture information about the items and to load the information into a computer with minimal human labor.
One type of automatic identification technology is radio-frequency identification (RFID). RFID is a generic term for technologies that use radio waves to automatically identify objects such as tagged products. There are several conventional methods of identifying objects using RFID, the most common of which is to store a serial number (and other information if desired) that identifies the object on a microchip that is attached to an antenna. The chip and the antenna, together with any supporting substrate, herein are called an RFID device or an RFID tag. The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves from the RFID device into a form that can then be utilized by a computer.
As the name implies, .electronic article surveillance (EAS) is concerned with the embedding or attaching of a disposable security label or tag to a retail item to deter shoplifting. Conventional EAS devices or tags include a resonator that, when activated, causes an alarm to sound when the EAS tag is brought within operative proximity of detection apparatus (which is typically located at the exit of a store). However, if the EAS device is active, a similar signal will also be produced each time that a customer either properly removes purchased goods from the store or enters another store with similar detection apparatus. Generally, EAS tags are inexpensive and disposable items that are not removed from merchandise during check out (which is generally true for RFID tags as well). For these reasons, a variety of different techniques have been developed to deactivate EAS tags, typically by a clerk during check out using deactivation apparatus that needs no physical contact with the tag.
Various types of EAS devices and deactivation systems make use of specially configured tags or labels in connection with an apparatus for positively deactivating such tags or labels. A first example is the EAS tag described in U.S. Pat. No. 4,498,076 to Lichtblau. The Lichtblau tag is provided with a resonant circuit having a capacitor portion with an indentation that permits the resonant circuit to be deactivated according to methodology as described in U.S. Pat. No. 4,728,938 to Kaltner, for example. The Lichtblau EAS tag is readily deactivated at the point of sale by subjecting the tag or label to a relatively high-powered signal which, because of the mechanical indentation, is sufficient to cause a short circuit within the tag or label for deactivation.
Another type of EAS tag, sometimes called a magnetomechanical EAS tag, uses the technology disclosed in U.S. Pat. No. 3,765,007 to Elder. Magnetomechanical tags include an active element and a bias element. When magnetized, the bias element applies a bias magnetic field to the active element which causes the active element to be mechanically resonant at a predetermined frequency upon exposure to an interrogation signal which alternates at the predetermined frequency. This tag requires a relatively high magnetic field level for activation and deactivation. Activation and deactivation is accomplished by exciting a coil wound around a magnetic core.
One of the concerns consumers have with RFID tags is privacy. More specifically, consumers may believe that their spending habits and mobility can be tracked by means of still-active RFID tags attached to their purchases. Accordingly, to increase consumer confidence in RFID technology, manufacturers are challenged to improve RFID tags so that the tags are no longer activated by far-field RF signals once tagged products are purchased or used by consumers.
Accordingly, RFID devices and EAS devices serve different purposes when it comes to retail items. As used in the present patent application, the terms “EAS device” and “RFID device” may refer to devices that are embodied in separate tags or to devices that are combined in the same tag. By and large, each of the systems utilizes different apparatus and methodology for activation and deactivation. Therefore, retailers may need to purchase and install separate systems for implementing and deactivating RFID and EAS functionality in their stores, which can be burdensome and expensive.
In view of the foregoing, there is a need in the art for RFID and EAS technology that allows the RFID functionality of tag to be disabled easily and inexpensively. The present invention satisfies this need.